The disclosure is directed to a multi-mode optoelectronic observation and sighting system with cross-platform integration capability.
Due to its core principle of operation, in other words, intensifying existing light, night vision technology has its limitations. For example; inability to detect objects/targets when there is no ambient light available and/or when the object is camouflaged or when the image is obstructed with foliage, smoke, fog or camouflage net.
Operation of a LWIR thermal imaging sensor is based on retrieving and processing long-wave infrared radiation signal and converting it into a visible video image. Although it does not require any visible light to successfully operate, a thermal imager still cannot detect objects if their temperature is the same as that of the environment. Likewise it cannot sense and record any information about an object if that object is located behind a medium or barrier that does not transmit infrared (IR) radiation, such as conventional glass.
A complementary combination of a daytime camera, a thermal imaging and night vision devices that substantially eliminate the vulnerabilities of each individual system and significantly increases user's scene comprehension and situation awareness is therefore desired. However portable, lightweight, and cost-effective real-time and lag-free overlay of different video channels input that will achieve this is yet to be made.
For example, US Publication No US2007/0103773A1, is directed to fusion night vision system with image intensification and infrared imaging capabilities. The disclosed technology is achieved using dichoptic stimulation (i.e. brain fusion), Optical overlay using beam splitter/combiner, and digital fusion. Similarly, US Publication No US2007/0228259A1, is directed to a system and method for fusing an image. The features disclosed involve digital or analog fusion mixer (with no further disclosure of how this proposed approach is to be implemented into fully operable apparatus), parallax compensation circuit coupled to the display and digital image resizing.
Also, US Publication No US2009/0058881A1, which is directed to a fusion night vision system with parallax correction, discloses digital fusion, which is not cost-effective.
Moreover, Canadian Application CA02470070-2008-09-10, directed to video-enhanced night vision goggles discloses video scaling and fusing in a digital way using field-programmable gate array (FPGA). The invention uses an I2 Tube coupled to a CMOS camera via a micro-channel interface.
Furthermore, U.S. Pat. No. 8,836,793 directed to true colour night vision fusion, uses beam splitter for VNIR and LWIR separation and preserves the colour information of the VNIR channel while the LWIR channel video image is being processed for edge detection whilst LWIR video processing is done digitally.
Accordingly, the available instruments and technology is based on Brain fusion (dichoptic stimulation)—each eye receives separate video image (LWIR or VNIR) and fusing is done in the operator's brain, therefore cannot be used in monocular devices or any display (e.g., LCD); on Beam splitter/combiner (optical overlay), which is prone to parallax issues with the eye position according to the eyepiece, since both images are not projected on the same plane. Furthermore, beam combining also increases the size of the device by adding the extra needed optics and also adds to the costs. Finally, the available technology uses Digital processing—very precise and versatile, but has increased cost due to the need of fast digital processing ICs, frame buffering, etc. Digital processing may also introduce latency if the video processing unit is of a lower speed.
There is therefore a need for a multi-mode optoelectronic observation and sighting system with cross-platform integration capability, which does not introduce any latency, where the signals are mixed real-time on the fly without frame buffering, can be displayed on bi- and/or monocular devices and screens and offer lowered cost of the solution.